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Sunnie, that's why "touch DNA" is considered experimental and not allowed in US court rooms!

US court rooms have been very reluctant to accept TDNA but it is, unfortunately, starting to make some inroads. With respect to admissibility, TDNA has been in the court room but, of course, has been challenged in both of the cases that I’m aware of.
It won the challenge once, and lost once, so it will continue to be challenged until such time as a more definitive ruling can be obtained.

A controversial new technique in DNA Testing and Criminal Evidence is being challenged in a Murder case in Supreme Court, Queens County…[SNIP]"Trace" DNA or "Touch" DNA, also known as "low copy number" DNA, a technique with serious limitations, developed and used in the United Kingdom, is key evidence in the case of People v. Hemant Megnath…
[SNIP]Mr. Greenberg, Defense Counsel for Mr. Megnath, petitioned the Supreme Court, Queens County, Judge Robert Hanophy, for a "Frye" Hearing, wherein the Prosecution must establish that scientific evidence, before admission as evidence at trial, be "sufficiently established to have gained general acceptance in the particular field in which it belongs". As examples, the results of Breathalyzer tests in DWI cases, "conventional" DNA results and fingerprint results, have met the Frye standard and such evidence is admissible in a criminal trial. Conversely, the results of a "lie Detector" test are inadmissible in that the science has not fully been accepted in the relevant scientific community.
Judge Hanophy's Decision has important ramifications for the admissibility of "Touch" DNA evidence in future cases in New York and the United States: If the Judge finds scientific acceptance, such evidence will be admitted routinely in criminal cases.http://www.addabboandgreenberg.com/P...s-County.shtml
The decision was in favor of allowing the testing:A Queens judge has become the first in the nation to approve a controversial DNA-tracking technique that can nail criminals with a speck of blood or the mere touch of a finger.
Wednesday's precedent-setting decision by Supreme Court Justice Robert Hanophy came in the case of Hemant Megnath, a man prosecutors say slashed a young woman's throat just before she was about to testify against him in a rape case.http://www.nydailynews.com/news/crim...#ixzz2KI8KBbZj

Low Copy Number DNA Fryed in California
Another recent development is the Frye hearing victory by a team of Los Angeles public defenders headed by Jennifer Friedman that resulted n low copy number analysis. This kind of test is performed when only very small samples are available for testing, and is not uncommon. With such small samples, all sorts of confounding artifacts can interfere with the reliability of the test. The defense team convinced the trial judge in People v. Hector Espino (March 18, 2009) that there has been insufficient validation research done on the methods used to produce and interpret the results of low copy number cases. http://www.state.il.us/defender/ctne...me1_issue1.pdf

Though it takes some uncovering, the debate within the forensic community over the use and reliability of LTDNA still rages, especially in the USA. There, the admissibility of LTDNA (sometimes referred to as “touch DNA”, “low copy DNA” or “low-level DNA”) in criminal cases has been far more controversial than in the UK. Eminent experts including Dr Bruce Budowle (Department of Forensic and Investigative Genetics, University of North Texas Health Science Center, Fort Worth, Texas, USA and ex head of the FBI’s DNA laboratory) have spoken out against the forensic use of LTDNA as evidence in criminal trials.
Professors Krane and Mueller continue to be skeptics, and broadly take the view that “fit for purpose” should mean limiting that purpose to the generating of intelligence leads. US courts have recently taken differing and contradictory approaches to admissibility. The decisions known to the authors have been from courts equivalent to our Crown Court, not appellate decisions, and they arise from litigation within the state, as opposed to federal, court system. In a case before a New York court, LCN evidence was ruled admissible, while in California the court was concerned with the dangers inherent in LTDNA–stating that “based on the evidence before the court, that there is no general acceptance in the scientific community as to the procedures to be used once you’re dealing with a LCN sample, there’s no general acceptance as to how to interpret the results that you would get when you begin with a LCN sample, and there’s no general acceptance as to the statistics that can be applied to those results.” The court went on to rule the test results in that case inadmissible. In this jurisdiction, challenges to admissibility will now be relatively rare, given the guidance from the Court of Appeal in Reed. But if LTDNA evidence is to be properly understood by juries and not given undue weight in a particular case, then lawyers will need to understand the limitations and shortcomings of this type of evidence. Indeed not all DNA evidence is equal. http://www.doughtystreet.co.uk/files...e%20DNA%20.pdf

With Touch DNA in that case, there was a known DONOR. His skin cells on the victim DO point to his having actually "touched" her. In JB's case, there IS no known donor, so I can't imagine that holding up in court.

This is my Constitutionally protected OPINION. Please do not copy or take it anywhere else.

If skin cells transfer by touch to another person or object, it stands to reason the same skin cells can leave the touched person or object by secondary transference.

Am I all wet in my thinking?

No you're not.

How do people transfer/deposit skin cell DNA?

•Whether or not a usable profile is found from touch DNA is dependent on a number of factors:

•The shedder profile of a person. Are they a good shedder, in other words do they have a tendency to leave more of their DNA and pick up very little, or are they a poor shedder that leaves little of their own DNA and picks up significant foreign DNA?
•The length of contact with a particular object
•The pressure of contact with a particular object
•Do they wash their hands frequently or infrequently?
•Do they have a tendency to contact their face frequently or infrequently?
•The type of surface involved, is it textured or smooth?
•Is the environment hot or humid and likely to cause rapid degradation?
•Are there biological elements in play that may cause rapid degradation?
With all that in mind you must also remember that DNA is sampled in such a way as to try to minimize the area involved and, therefore, minimize the amount of “stray” DNA donors being found.

•SHEDDER INDEX
A group of 29 people were tested for their ability to deposit their DNA profile onto touched objects. It was found that a typical good shedder leaves a complete profile on the surface of a plastic tube after contact of only 10 seconds, whereas at the other end of the scale a poor shedder will leave only a few alleles, possibly with several loci dropping out completely.

•PRIMARY TRANSFER
Work was carried out to determine whether DNA profiles could be obtained from clothing; specifically, plain white T-shirts. After 8 hours wear, more of the wearer’s DNA was recovered from the front of the Tshirt than the back. Targeting the neck area maximized the chance of obtaining a useful result. In a series of simulated assaults, where one person grabbed the shoulder of another for a period of 30 seconds, mixed profiles were obtained from the grabbed area of the T-shirts. The “assailant” always contributed the major component to this mixture, regardless of his/her shedder type.

•SECONDARY TRANSFER
Experiments were carried out to determine whether it was possible for individual A to transfer his DNA to individual B through contact, who could in turn transfer A’s DNA onto an object. We began with a scenario which was most likely to yield a result: a good DNA shedder (A) shook hands with a poor shedder (B), who then gripped a plastic tube for 10 seconds. The results from swabs of the tubes showed that on five separate occasions all of the good shedder’s profile was recovered, with none of the poor shedder’s alleles appearing. The experiment was then repeated, but with the introduction of a delay of 30 minutes between the time of the handshake and the tube-holding. The results indicated that although the poor shedder deposited some alleles, secondary transfer of the good shedder’s DNA still occurred.

•PERSISTENCE
Many factors may affect the persistence of low level DNA; time, temperature, humidity, etc. While it is unreasonable to test every combination of variables, some generic experiments have been undertaken and certain scenarios addressed. A time-study of the persistence of DNA is currently underway, where touched items have been stored at room temperature and tested to find out how much DNA can be recovered after certain periods of time. full profiles were still recovered from surfaces touched by a good shedder even after 4 months, whereas a marked decrease in the recovery of the poor shedder’s DNA was observed.
An exchange of identical wrist-watches between certain shedder types was carried out to ascertain the period of time needed for the original wearer’s DNA profile to be replaced by that of the new wearer. Generally we found that a good shedder completely replaced the original wearer’s profile in 2-3 weeks, and after only a few days had become the major component of a mixture. An example of this is shown in In contrast, a poor shedder typically took around 2 weeks just to comprise the major component.http://www.promega.com/geneticidproc...nts/murray.pdf

We have shown that there is a difference between individuals in their tendency to deposit DNA on an item when it is touched. While a good DNA shedder may leave behind a full DNA profile immediately after hand washing, poor DNA shedders may only do so when their hands have not been washed for a period of 6 h. We have also demonstrated that transfer of DNA from one individual (A) to another (B) and subsequently to an object is possible under specific laboratory conditions using the AMPFISTR®SGM Plus™ multiplex at both 28 and 34 PCR cycles. This is a form of secondary transfer. If a 30 min or 1 h delay was introduced before contact of individual B with the object then at 34 cycles a mixture of profiles from both individuals was recovered. We have also determined that the quantity and quality of DNA profiles recovered is dependent upon the particular individuals involved in the transfer process. The findings reported here are preliminary and further investigations are underway in order to further add to understanding of the issues of DNA transfer and persistence.http://www.sciencedirect.com/science...h&_sort=d&_doc anchor=&view=c&_acct=C000050221&_version=1&_urlVer sion=0&_userid=10&md5=52d90b1ae7d70c8cc6b96f57dc40 7596

Objects handled by many individuals all produced profiles with multiple alleles of varying intensity. To determine the effect of multiple handlers, we exchanged polypropylene tubes between individuals (2 or 3, 10 min each) with different genotypes. Although the material left by the last holder was usually present on the tube, that of previous holders was also retrieved to varying extents. The strongest profile obtained was not always that of the person who last held the object, but was dependent on the individual. We regularly observed profiles of previous holders of a tube from swabs of hands involved in these exchanges, showing that in some cases material from which DNA can be retrieved is transferred from object to hand (secondary transfer).http://www.bioforensics.com/conferen...ngerprints.pdf

The presence of DNA with a profile matching that found on an item does not necessarily show that the person ever had direct contact with the item. “It has also been shown that a full profile can be recovered from secondary transfer of epithelial cells (from one individual to another and subsequently to an object) at 28 cycles [the standard method].”
“The full DNA profile of one individual was recovered from an item that they had not touched while the profile of the person having contact with that item was not observed. This profile was also detected using standard 28-cycle amplificationhttp://www.theforensicinstitute.com/...tamination.pdf

Secondary transfer refers to the fact that, through physical contact with other people, individuals can inadvertently carry and deposit other people’s DNA onto objects of evidence. For example, two people shaking hands will transfer their own DNA to each others’ hands. If each then goes on to touch another object such as a coffee mug, baseball bat, knife etc., they could transfer the other’s skin cells to the object. If that object is a murder weapon, the identification of DNA through LCN could prove problematic and misleading.
• Variable shedding refers to the extent to which different people shed their skin cells in different quantities under different circumstances. Some people are more likely than others to leave behind their DNA in the form of skin cells. Through research at the FSS, it has been found that there are, for example, “heavy shedders,” “medium shedders,” and “light shedders.” Thus, the last person to touch a particular object may not leave the most DNA or strongest profile.
• The amount of DNA deposited can also be affected by certain actions taken by the individual. Washing of one’s hands will, for a period of time, decrease the amount of skin cells a person deposits on other objects. Additionally, the amount of perspiration exerted at the time the object is being held may also affect the amount of skin cells that are deposited. Both of these scenarios could adversely affect results upon LCN-DNA analysis.
• Given the nature of variable shedding and secondary transfer, the risk of obtaining a mixture is increased when applying a technology with increased sensitivity such as LCN. It is impossible to amplify the “right” DNA profile because all of the DNA that is contained in a biological evidence sample will be amplified.http://www.ncjrs.gov/pdffiles1/nij/grants/203971.pdf

“It has also been demonstrated that DNA containing material can be deposited onto surfaces that without physical contact being made. In 2003, Rutty carried out a series of experiments to determine the extent to which a crime scene could be contaminated by crime scene investigators (Rutty et al. 2003). A series of experiments were carried out to investigate the level of DNA deposition after 15 minutes of silence or talking, with and without physical activity. The level of DNA deposition after 10 seconds coughing was also tested. The results of these experiments showed that high levels of DNA could be detected after 15 minutes of talking, whilst kneeling, even when a face mask was worn. It was hypothesized that the detected DNA could have arisen from orally projected saliva particles or could be due to the sloughing of epithelial cells around the area that the face mask was in contact with the face (Rutty et al. 2003). In order to distinguish the contribution of orally projected biological material from shed epithelial cells a second set of experiments were conducted by Rutty‟s group (Port et al. 2006). These follow-up experiments greatly simplified the model used in Rutty‟s original work to investigate orally projected biological material only. The results of these experiments showed that DNA-containing biological material could be detected up to 184cm (72 inches) away from the donor and a full DNA profile could be detected in the area immediately in front of the donor after only 30 seconds of talking (Port et al. 2006).”https://lra.le.ac.uk/bitstream/2381/...%20VERSION.pdf

Transfer of DNA is seen with variable degrees of efficiency in each of the two types of transfer experiments conducted. In most cases the transferred DNA was a lower concentration than the DNA of the individual to whom it was transferred, however, this was not observed in all instances.
In the experiments involving a kiss to the face, DNA or cells containing DNA were transferred b a kiss to an individual’s face and then to a glove in all of the experiments fun in this study.
In the experiments involving transfer of DNA via a towel, DNA or cells containing DNA were transferred to a towel, then to an individual’s face and then to a glove in all experiments with one of the towels and in none of the experiments with the other towel. In each of these sets of experiments the towel was exposed to the individuals DNA from only one face washing and drying. Larger quantities of DNA would be expected to be deposited on the towel from multiple uses of the towel. http://www.bioforensics.com/conferen...on%20Study.pdf

• Strengths and Weaknesses of touch DNA

-CBI Laboratory Agent Schleicher
First, "touch DNA," like standard DNA and fingerprints for that matter, doesn't tell the investigator when the DNA was left on the evidence. It could have been left an hour ago or a week ago. Of course the investigator may be able to narrow down the time range based on certain facts of the particular case.
An example is a suspect's baseball cap left behind at a murder scene. The lab swabs the inside and outside of the hat. A DNA profile from two individuals is developed. Even if there's more DNA from one contributor than the other, you still can't say who was wearing the hat at the time of the murder.
Also, "touch DNA" is so sensitive that it's possible to pick up background DNA. For example, if a shirt is made by hand, then someone has touched the shirt even before it's packaged and sold. It's possible "touch DNA" could liberate these skin cells from the evidence, even though this person has nothing to do with the investigation.
And of course, "touch DNA" doesn't tell the investigator how the DNA made its way onto an item. It doesn't provide the culpable mental state of the individual that committed the crime.
It's up to the lawyers to argue whether the "touch DNA" is the result of a casual contact, or from the suspect forcefully grabbing the victim's shirt. The bottom line is that good police work is necessary to piece together the events surrounding the commission of the crime.
Schleicher wants agencies to be aware of the power and limitations of the technology. Agencies need to clearly understand the questions they want answered. Why is this piece of evidence important? What will it tell me about the commission of the crime? Law enforcement agencies just need to be prepared for the answers, even if the answers aren't what they were expecting.http://www.policemag.com/Channel/Tec...t-a-Touch.aspx

• The dangers of touch DNA

I am familiar with "Touch DNA" and limitations to this technique which includes the following:
a. No body fluid has been identified for the samples tested. If a DNA profile is identified in a "touch" or "contact" area, the result may be from an individual with no relation to the crime.http://cspl.uis.edu/ILLAPS/Service/D...teResponse.pdf

• What precautions were taken in the Ramsey case, what precautions should have been taken?
Highly sensitive tests require a great deal of care in evidence collection, handling and storage.
This is from a recent interview between Evidence Technology Magazine and Joe Minor-Technical DNA Manager & Special Agent-Forensic Scientist Supervisor, Tennessee Bureau of Investigation:

Have you ever thought about what happens to objects when you breathe on them, cough or sneeze near them, talk over them, or even adjust your glasses or wipe your brow while wearing gloves? All of these offer the potential to deposit your DNA on surfaces, usually unknowingly!
Remember when we used to wear gloves and masks to avoid getting something from a body or scene? Technology has changed the way we need to do our business.
Our intent is to provide a brief overview of what can happen at scenes, in a lab, morgue or autopsy room, and what information can be obtained from DNA as analyzed at the Colorado Bureau of Investigation.
What are some precautions we can all take to minimize this “trace DNA” from ourselves? This is the classic two-edged sword. We have the sensitivity to get identifiable DNA from someone’s finger touching a light switch or doorknob (such as a perpetrator); however, this same sensitivity can allow our own DNA to be found during an analysis!
Since we are analyzing small amounts of DNA, there is also the potential of removing DNA from an item that may have significance to the case.
Let’s address DNA concerns at the scene, in the lab, morgue or autopsy room and finally the information we can obtain from DNA analysis.

Scene:
The weapon such as the grip of a firearm, the trigger of a firearm, or the handle of a knife may have DNA from the person who handled that weapon.
The body of the deceased may have DNA from someone who has manually strangled the victim. A ligature used to bind or strangle may contain DNA.
Clothing items may contain DNA of someone who has handled the clothing of the deceased.
Skin touched in the process of moving a victim in some fashion or dressing or undressing a victim may have foreign DNA.
A suspect (or anyone) may also leave DNA if they happen to cough sneeze, or spit accidentally (while talking) over or on the deceased. The doorknob used to enter and exit the room or other objects that may be present in the path from the entry way to the body.

Morgue, autopsy room, or lab:
The items mentioned above need to be handled with caution if they do end up in one of these places, especially the clothing items. Remember the removal of DNA is as significant as the addition of your DNA to an object.
We need to think about the potential for contamination from previous deceased, autopsies, or evidence; even scissors that are used to cut clothing from one body may transfer DNA to a second body or object if not cleaned.http://coloradocoroners.org/newsletters/summer2007.pdf

Further regarding touch DNA, these are the comments of an experienced Crime Scene Investigator:
"Touch DNA?" My understanding is that this is no different than DNA taken from a swab of a door handle, the trigger of a handgun, the handle of a knife, and on and on. It is DNA analysis from skin cells, which has been a primary venue, to my knowledge, since 1996. At least that is the first forensic case I had in which a profile was gotten from skin cells from an object. If this is the case, there is nothing new and the article is sensationalizing the analysis. I noticed that the news article stated that the "touch DNA" produced the same profile as the previous DNA analysis of the panties. Hence, there is no new information corroborated by the news release. Why now, does the analysis exonerate any family member, and it didn't in 1996. Wouldn't one expect to find additional sources from skin cells consistent with those from the crotch on the underwear?
It is a common phenomenon that there are unidentified DNA profiles, particularly in mixed profiles, in many DNA analyses. As an example, the steering wheel of an automobile often produces mixtures. I have seen mixtures from the underwear, often, of sexual assault victims. It is further not uncommon to not be able to identify some of the profiles. I currently have four "John Doe" sexual assault warrants active with full 16 value DNA profiles in CODIS. They have been there for about 5 years. I have yet to receive a hit on any of those profiles. These are all from the underwear of sexual assault victims. Thus, unidentified DNA on underwear is not uncommon.
The third fallacy in the reasoning is that lack of DNA of a family member and an unidentified DNA profile does not exonerate any one person. DNA, standing alone, does not prove nor disprove involvement in a crime. It only can lead to a reasonable inference that a given persons DNA was not on a given object or was on a given object. It is the other information in a consilient relationship that leads to the probable cause of the involvement of a given person(s) in a crime.
As a final note. I know of four cases from my limited case work in which nuclear DNA and mitochondrial DNA did not match. How did this happen. In two cases there was a link between probable lab cross contamination. This was verified by a DNA lab analyst statement (a very mature and professional position, by the way by the analysts). The third case was a suspected intentional switch of samples by a disgruntled lab analyst. This case was never resolved by legal mitigation, but the lab analyst left for another position. The fourth case is in the unknown bin. Within the last five years I worked a case in which a substrate had been examined by a state forensic lab with the results that the object contained no DNA and no blood source. The same object, a piece of clothing, was sent to the FBI and the result from the FBI analysis was that there was not blood and no source for DNA. As a result of cold case funds, the item was dug out of storage and treated with fluorescein. A few small spots reacted. These spots were swabbed and sent in for DNA analysis. A full DNA profile was obtained from these swabs. Further, a CODIS match was obtained from these swabs. The CODIS match was from a totally unknown source to the original investigation. The point is that DNA is a very powerful investigative technique, but there are many issues with DNA. Primarily, as we are coming to find out, the primarily issues have to do with the origin of the DNA which at the very minimum requires additional corroboration of the probability of the source contributing as an actor in a given criminal event.
It can be inferred that the recent press release is an effort to manipulate the investigation towards a specific insinuated conclusion. I see it as the effort of a prosecutorial office to conspire to wipe egg from the messy faces of past feedings on uncorroborated information.

Crime lab officials here and elsewhere don't like to talk about the fact that the same test that can link someone to a crime scene with a few minuscule cells left on a doorknob can also be contaminated by a passing sneeze. Or that DNA tests are only as reliable as the humans doing them -- a troubling prospect when dealing with evidence that has the power to exonerate suspects or imprison them for life.
"The amazing thing is how many screw-ups they have for a technique that they go into court and say is infallible," said William C. Thompson, a forensic expert and professor of criminology and law at the University of California-Irvine, who reviewed the incidents at the request of the P-I.http://www.seattlepi.com/local/183007_crimelab22.html

The following is from BFS Forensic Services:

Why have this evidence checked?
Although the statistics regularly applied to DNA can appear very strong evidence, this does not necessarily mean that direct contact has occurred. There are various other aspects that should be investigated, such as the possibility of secondary transfer, for example via another person, whether any contamination may have occurred, or the chance of the DNA being deposited by indirect contact, such as coughing over an item.http://www.forensic-science.uk.com/bio.htm

• What is the probative value of touch DNA?

Many people mistakenly give all DNA evidence the same probative value.
Of course, DNA can be incredibly incriminating, however, that is true only if it derived from bodily fluid sources such as blood, or semen, for example.
How should we treat DNA evidence obtained from skin cells?
Because of the “mobility” of this DNA, it is not possible that it should carry the same weight as DNA from bodily fluid. It should be of approximately the same value as hair and fiber, and of lesser significance than fingerprint evidence.

Here is an opinion from a seasoned forensic biologist and DNA expert who clearly outlines that not all DNA has the same relevance.

The DNA vs. Fingerprints Debate
…
This raises the question, which of the two types is the stronger evidence? Answer: Fingerprints - and I say this as a DNA expert.
…
We also consider the nature of the transfer of evidence. If I were to touch a smooth surface such as a wall, I would deposit DNA and leave some fingerprints behind on the wall. This is called ‘direct’ or ‘primary’ transfer. However, if someone was to come along and wipe that wall with a cloth, it would remove my DNA onto the cloth and wipe the fingerprint off. If that person then uses that cloth to wipe the door handle, my DNA can then be transferred on to that door handle. Therefore, my DNA could be recovered from that handle without me ever coming into contact with it. This is referred to as ‘indirect’ or ‘secondary’ transfer. In this example, my DNA is transferred, but my fingerprint is not. This means that if my fingerprint is found on a surface, then I must have touched that surface; whereas, if my DNA is found on a surface, then I may have come into contact with that surface or it got there by secondary transfer.
-Graham Williamshttp://www2.hud.ac.uk/sas/comment/gw260609.php

US court rooms have been very reluctant to accept TDNA but it is, unfortunately, starting to make some inroads. With respect to admissibility, TDNA has been in the court room but, of course, has been challenged in both of the cases that I’m aware of.

It won the challenge once, and lost once, so it will continue to be challenged until such time as a more definitive ruling can be obtained.

Thanks, Cynic, for that information. I wasn't aware "touch DNA" had actually won a challenge to be used in a US court.

Once we go down that slippery slope, we're in trouble. With the idiotic juries that are sometimes seated these days, a few skin cells might be enough to convict an innocent person, or more often, let a guilty perpetrator go free. "Touch DNA" is nothing but Pandora's Box in a test tube.